Metadata from two videos posted on Friday by Russia-backed separatists announcing an immediate evacuation of civilians from Ukraine’s tense border regions show the files were created two days ago.

The video by Denis Pushilin, head of the Donetsk rebel government, said Russia has prepared facilities.

Mr Pushilin alleged in the Telegram video statement posted on Friday afternoon that Ukrainian President Volodymyr Zelenskyy was going to order an imminent offensive in the area.

Leonid Pasechnik, head of the Luhansk rebel government, posted a similar video on his own Telegram channel on Friday afternoon.

Telegram retains metadata, which includes by default the date a file is created.

US authorities have alleged that Russia has planned an invasion all along, and said the Kremlin had planned pre-recorded videos as well as part of a disinformation campaign.

Meanwhile, the White House has accused Russia of being responsible for recent cyberattacks targeting Ukraine’s defence ministry and major banks.

The announcement from Anne Neuberger, the White House’s chief cyber official, was the most pointed attribution of responsibility for cyber intrusions that have unfolded as tensions escalate between Russia and Ukraine.

The attacks this week were of “limited impact” since Ukrainian officials were able to quickly get their networks back online, but it is possible that they were laying the groundwork for more destructive intrusions, Ms Neuberger said.

She said the US had rapidly linked the attacks to Russia and was publicly blaming the Kremlin because of a need to “call out the behaviour quickly”.

She said there was no intelligence indicating that the US would be targeted by a cyberattack.

Ukrainian officials called Tuesday’s distributed denial of service attacks the worst in the country’s history. But while they definitely disrupted online banking, impeded some government-to-public communications and were clearly intended to cause panic, they were not particularly serious by global or historic standards, said Roland Dobbins, the top engineer for DDoS at the cybersecurity firm Netscout.

“Most DDoS attacks succeed due to the lack of preparation on the part of the defenders,” said Mr Dobbins, adding that most commercial mitigation services designed to counter such attacks would likely have been able to fend off Tuesday’s attacks.